Thursday, 8 December 2016

Debunking the climate change deniers

While
we’re still talking about trolls

Climate
Deniers’ Top 3 Tactics

Climate
deniers don’t just want to deny global warming and its danger. They
want you to
deny it too.

But
man-made climate change is real, the danger is extreme, so they have
to use guile to persuade you otherwise. There are three
tried-and-false tactics they use often, and to great effect. Let’s
take a close look at these misdirection methods, so you can arm
yourself for defense against the dark arts.

#3:
REJECT THE DATA

Climate
deniers don’t like what the data say. What they probably hate most
is the temperature data — especially at Earth’s
surface (where we live) — because it shows so plainly and obviously
that the world is heating up. Here are the three best-known
global-average surface temperature data records (yearly averages
since 1880), from NASA, NOAA (the National Oceanic and Atmospheric
Administration), and HadCRU (the Hadley Centre/Climate Research Unit
in the U.K.):

They
all tell pretty much the same story: Earth is heating up.

Pinning
down global average temperature change is a complicated business. You
have to gather data from around the world, including thermometer
readings from thousands of surface stations for land areas and sea
surface temperature measurements from ships and from satellites. You
have to average them properly, in a way that doesn’t over-emphasize
regions with lots of observations but underplay regions more sparsely
observed (a process sometimes called “area-weighting”). You need
to remove the seasonal cycle, because we’re not interested in
whether summer is hotter than winter, we want to know whether the
world as a whole is heating or cooling. You have to watch for things
like station moves where temperature seems to
change only because the station was moved to a hotter or colder
location. Truly, it’s a complicated business.

The
longer they’ve been doing it, the better they’ve gotten at it. In
particular, they’ve learned to spot the signs of data problems and
make adjustements to compensate. As a result, they’re a lot better
at it now than they were just a few decades ago.

But
because there are “adjustments” — whose only purpose is to make
thing better by compensating for known problems — deniers have
seized on that word to claim that the scientists doing it were
perpetrating a fraud, that adjustments were only to introduce false
warming into the record.

Richard
Muller, a physicist at Berkeley University, thought that maybe they
were right about that — he was highly suspicious
of the surface temperature data. He decided to find out for himself,
by organizing a team to go back to the original, unadjusted
data, and use the most sophisticated and mathematically sound
procedure for estimating a world-wide average, one which didn’t
allow any way to make the results “lean” one way or the other to
introduce a bias toward cooling or warming. The effort is called
the Berkeley Earth Surface
Temperature project.

Climate
deniers were thrilled — they waited in anticipation of genuine
scientists, using the best available methods, finally showing that
the existing records were wrong.

The
admiration of climate deniers for the Berkeley Earth Surface
Temperature project didn’t last long. It vanished into thin air as
soon as the results were announced. That’s when the climate denier
community turned on Richard Muller like a pack of wolves, because the
Berkeley Earth Surface Temperature project, the fakeproof method,
showed that the
existing data sets got it right all along.
Muller himself had this to say in a 2012
op-ed in the New York Times:

CALL
me a converted skeptic. Three years ago I identified problems in
previous climate studies that, in my mind, threw doubt on the very
existence of global warming. Last year, following an intensive
research effort involving a dozen scientists, I concluded that global
warming was real and that the prior estimates of the rate of warming
were correct. I’m now going a step further: Humans are almost
entirely the cause.

And
how does the new Berkeley Earth data set compare to the others? Like
this:

Climate
deniers don’t just use this tactic on temperature records; when
data disagree with their narrative they’ll attack the data.
Far too often, they won’t just say the data are
mistaken, they’ll accuse the scientists who put it together of
fraud. It’s reprehensible.

Climate
deniers like to call themselves “skeptics,” but they’re not.
What’s the difference? I think Neil deGrasse Tyson said it best:

“A
skeptic will question claims, then embrace the evidence. A denier
will question claims, then reject the evidence.”

#2:
DISTRACT FROM THE TREND WITH FOCUS ON FLUCTUATIONS

Almost
all data is a combination of trend, which has
persistence, and fluctuation, which doesn’t last. The
trend reveals how climate is changing, but the
fluctuations are weather, and just because climate
changes, doesn’t mean we won’t still have weather. Fluctuations
go up and down and down and up — they just won’t stop — but
they never really get anywhere.

Climate
scientists can tell you, it’s the trend that
matters. Heat waves, flood, drought and the like are things we’ve
always had to deal with, and they spell trouble. But when they
get more frequent, and more severe,
it can be disastrous. It costs money, it costs jobs, it costs lives.

Deniers
don’t want you to know how the trend is going, so they go out of
their way to shout about fluctuations that go the other way. Maybe
the most infamous example is when Oklahoma senator James Inhofe
carried a snowball onto the floor of the U.S. senate one day to try
to ridicule global warming. He ended up ridiculing himself, because
the idea that you can discredit global warming because you happened
to find some cold weather — in winter, no less — is truly
ridiculous. As in, worthy of ridicule.

Temperature
is one of those things that fluctuates. It can show large swings from
day to day, from month to month, even from year to year. But there’s
also a trend, which is upward — it’s called global
warming. Lately deniers have been taking temperature fluctuations
that happen to go downward and braying about “global cooling.” Of
course the fluctuations don’t last — but they still accomplish
their goal of creating doubt in the minds of the scientifically
naive.

Christopher
Booker writes for the British newspaper The Telegraph. He
recently included a comment about England’s meteorological office
acquiring a new computer for their weather and climate simulations,
in which he had this to say:

“Only
gradually since 2007, when none of them predicted a temporary fall in
global temperatures of 0.7 degrees, equal to their entire net rise in
the 20th century, have they been prepared to concede that CO2 was
not the real story.”

— Christopher
Booker, U.K. Telegraph, 22 October 2016.

It
that true? Did global temperature actually fall far enough to negate
the entire 20th-century rise? Here’s Earth’s average temperature
change each month from 1880, according to NASA:

If
we zoom in on the last 40 years or so, starting about 1975, we can
easily see what it is Christopher Booker is talking about:

He’s
talking about a couple of fluctuations. If you compare an especially
high fluctuation to an especially low fluctuation, you might convince
yourself that temperature is falling fast.

But
a fluctuation is not a trend. Trends have some persistence;
fluctuations don’t last. Climate scientists tell us that it’s the
trend that matters — that’s why it’s what they talk about:

Another
example: about a week ago David Rose had an article in the U.K. Daily
Mail with its focus on a “sudden drop” in global
temperature. Rose searched far and wide to find a data set he could
use to make that claim, and the best he could come up with was
satellite data for the lower atmosphere (not at the surface) over
land areas only (excluding the 2/3 of the world covered by ocean).
His story was repeated by others in the U.K. Spectator and
the alt-right propoganda-driven Breitbart News.

What’s
fascinating is what they chose to focus on: some fluctuations which
they seemed to think were worth shouthing about, with no mention of
the trend. Here, in blue, are the fluctuations they made
such a fuss about, and in red is the trend they didn’t want to
discuss:

Fluctuations
will always be with us, they’re part of nature. But the rising
trend of global temperature that we’ve been seeing is man-made.
According to the overwhelming majority of climate scientists, this
trend spells trouble. And the reason? Mainly, it’s CO2.

We
now come to the most common, most pernicious, and probably most
effective climate denier tactic:

#1:
CHERRY-PICKING

On
April 15, 2013, Lawrence Solomon published a brief article
in the Financial
Post suggesting
that sea ice in the Arctic wasn’t really declining, that there was
no trend toward persistent long-term melting. He started with this:

Arctic
sea ice back to 1989 levels

Yesterday,
April 14th, the Arctic had more sea ice than it had on April 14,1989
– 14.511 million square kilometres vs 14.510 million square
kilometres, according to the National Snow and Ice Data Center of the
United States, an official source.

His
opening sentence is one of the most extreme examples
of cherry-picking: showing or talking about some evidence
that supports your claim, while ignoring or rejecting evidence that
contradict you.

He
went on to add a couple more cherry-picked “facts” for good
measure. Then he ended with this:

“The
only evident trend in the ice, as in the weather, is variability.”

It
all sounds pretty convincing, doesn’t it? Arctic sea ice was no
more extensive on that day than it was 24 years ago! Plus, he
actually mentions the words “trend” and “variability” — how
scientific.

The
following day (April 16, 2013) I posted this graph showing all the
available “sea ice extent anomaly” data from the National Snow
and Ice Data Center (yes, an official source):

In
case you’re wondering what’s happened since then, it’s this:

The
red line is an estimate the trend — the one that
Lawrence Solomon said isn’t “evident.”

This
particular example is also a case of tactic #2: distract from the
trend by focus on fluctuation. It’s executed by the never-ending
tactic of cherry-picking: discuss evidence that supports your claim
while ignoring or concealing evidence that contradicts you.

The
most frequent target of cherry-picking is temperature data. Here, for
instance is senator Ted Cruz’s favorite temperature graph:

I

t
certainly looks like there’s been no global
warming! But remember that data is a combination
of trend and fluctuation. Fluctuations
sometimes go down, which can make an upward trend look downward,
even when that trend — which we call global warming — hasn’t
stopped or even slowed. What deniers do is cherry-pick — find a
time span which starts with a large upward fluctuation, maybe even
ends with a large downward fluctuation, to create the false
impression of a downward trend.

In
1997-1998 we had a particularly strong el Niño, one of
the factors that can cause an especially large upward
fluctuation. That’s why climate deniers start so many
temperature graphs with 1997-1998 — it’s the large
upward fluctuation they need to give a false impression of trend.

But
that’s not the only time span one can cherry-pick to show
fluctuation and claim it’s a trend. There are many, which led to a
now-famous animated graph from the website Skeptical
Science:

No
matter how temperatures change, as long as there are fluctuations
deniers will be able to cherry-pick some time span to look like
their false claim. And there will always be fluctuations.

What
if we didn’t cherry-pick the time span? The data in Ted Cruz’s
graph starts back in 1979, well before 1997, and we’ve got some
more data since he showed it in his latest senate hearing. Here’s
the whole story:

T

he
red box shows the part included in Ted Cruz’s graph. The
interesting part, that reveals the upward trend, is what Ted
Cruz didn’t show.

Picking
an outlier for your start and/or end points isn’t the only way to
cherry-pick and hide the trend. Another is simply to pick a time span
that’s way too brief for the trend to make itself clear.

Fluctuations
can be large, especially for temperature data, and the trend can take
years to accumulate enough warming to overcome them. That’s one of
the reasons the typical time span to define climate instead
of weather is 30 years. If all you show is a brief
span of time, the trend doesn’t have long enough to “rise above
the noise.” But it’s still there.

The Global
Warming Policy Forum (GWPF) features a temperature graph in
their logo. The data are yearly average temperature according to the
Hadley Center/Climate Research Unit in the U.K. (HadCRU). Here’s
the HadCRU data itself:

The
year 2016 isn’t complete yet, but will be soon, so I’ve shown the
average for the year-so-far.

Here’s
the graph GWPF includes in their logo:

Notice
how it doesn’t start until 2001? Notice that it doesn’t include
2016’s year-so-far value? I wonder what they’ll do when 2016 is
complete and it’s harder to hide the temperature rise? Notice how
squeezed the data is into a small space, so the total
variation looks small? If they showed what came
before, or what came after, or even on a scale that helped see the
changes better, you might notice how clear the upward trend is.

There
are many ways to cherry-pick. Choose a time span selected to give the
wrong impression (start with 1997-1998); choose the one data set that
supports your claim but not any of the others; choose a single
event which bucks the trend (my grandmother smoked
cigarettes and lived to be 98 years old).

Climate
deniers use these tactics because they work. When they
suggest that the temperature data are a fraud, it raises your
suspicions. When they point out a “sudden drop” in temperature
data while concealing the trend, it can be persuasive. When you hear
that Arctic sea ice is no more extensive than it was on this date 24
years ago, it sounds convincing. When you see temperature data on a
graph starting in 1997-1998, it looks convincing.

Even
the best of us, even the smartest of us, are all too easily fooled by
misdirection (stage magicians can use that fact to make a very good
living). There’s no shame in being fooled by a charlatan, we’ve
all been taken in at one time or another. My hope is that now that
you’ve seen some of their tricks, when you run into them the next
time you’ll recognize them for what they are: tricks.